PRELIMINARY: The second rider on the slope was side hilling when the slide released. That rider was buried for 8 to 10 minutes and was evacuated by a helicopter about 2.5 hours later. The rider later succumbed to injuries. Two other riders were partially buried but not injured. The slide failed on a buried layer of surface hoar and dug down through several inches of faceted snow to a hard crust that formed in late November.